The field of the disclosure relates generally to displaying a navigation chart and, more specifically, to methods and apparatus for adjusting content and/or placement of symbols and/or labels based on available area in a navigation chart.
Navigation charts are used to plan and track aircraft flights. Initial computer displayed charts have been static pre-composed versions of traditional paper charts. Dynamic (e.g., real-time), electronically displayed navigation charts have additional challenges in terms of readability and operational approval for use by commercial operators. Dynamic, electronically displayed charts exist in other contexts, such as automotive navigation units. However, the context of dynamic aeronautical navigation demands more advanced display techniques than are available with existing implementations. For example, in an area of a chart with a high concentration of symbols and labels, known systems may omit labels for at least some symbols or abruptly move labels as a geographic position and/or orientation changes. Such compromises may impede interpretation of a chart and therefore be unacceptable in an aeronautical navigation system. For example, abrupt movement of labels is potentially distracting to a pilot.